The present invention relates generally to studs for articles of footwear, and more specifically to studs having variable ground interaction characteristics.
Athletes playing sports on grass or dirt surfaces often wear articles of footwear with studs attached to the sole. The studs assist the wearer in gripping the playing surface particularly to avoid sliding and allow for sudden turns and stops.
Studs are often designed for a particular playing surface. Studs may differ depending such factors as whether the surface is artificial, natural, soft, firm, wet, indoor, outdoor, or any other type of surface characteristic known in the art. Stud designs may also vary based upon the type of activity, as studs for soccer will differ from those for football. Studs for other particular types of activities may also be provided, such as studs designed for golf, diamond sports, track and field events, or the like.
Various stud configurations have been proposed. For example, U.S. Pat. No. 5,957,642 to Pratt teaches a cleat system for rapid and easy engagement to and disengagement from a shoe. The cleat system includes a nut and shank that may be attached to shoes. Pratt shows a number of different projections and ground engaging portions that may be used with the proposed nut and shank. The projections can be spike-type projections, soft spike projections, baseball-type projections, and soccer-type projections. The different projections illustrate a number of different studs or stud designs that are known in the art.
Stud designs include, among others, European Patent Application Number 0163823A1 to Mione. Mione teaches a screw-on stud for a sports shoe. The stud includes a washer, truncated-cone body, and a screw. The screw fits into a through-hole of a truncated-cone body and the centre hole of the washer. The stud is screwed into a recess of the sports shoe sole. The mating between the washer and truncated-cone body at an annular ridge allows the truncated-cone body to move without deforming the washer. The truncated-cone body may be made of metal such as aluminum or synthetic plastic resin such as nylon.
Another stud design is taught in U.S. Pat. No. 4,723,366 to Nagger, which teaches a cleat with reinforced radial support. The cleat includes a head, threaded stem, collars, flange, and skirt. The skirt is made of polyurethane or other durable and resilient synthetics. The remainder of the cleat is made of metal. The skirt is molded onto the flange during manufacturing so that axial forces applied to the head are evenly transmitted about the flange and the plastic skirt.
The prior art does not disclose a system that allows an athlete to customize a stud in order to vary the ground interaction characteristics of that stud. In particular, the prior art does not disclose the use of a plurality of rings that alter the contour, height, and material makeup of a stud in order to vary the ground interaction characteristics of that stud. Therefore, there is a need in the art for a system that addresses the shortcomings of the prior art discussed above.